Conventional key-in warning devices for ignition switches include a plunger that pushes upwardly on one blade until it connects with another blade to indicate to the driver that a key is in the ignition. Due to varying tolerances of ignition switches, the travel of the plunger often varies resulting in damage to the blades. In particular, as the plunger moves upwardly, the blades either bend beyond their yield point or slip off of the tip of the plunger. The uncontrollable variation of the travel of the plunger often results in deformation of the blades and poor contact between the blades.
Examples of conventional key-in warning devices include U.S. Pat. No. 5,066,941 to Lau, U.S. Pat. No. 3,806,676 to Krom et al., U.S. Pat. No. 3,806,675 to Krom et al., U.S. Pat. No. 3,138,789 and U.S. Pat. No. 2,613,258 to Azano, the subject matter of each of which is herein incorporated by reference.